Charles Butler was an English entomologist known for his significant contributions to the study of insects. He was particularly interested in the classification and behavior of various insect species, which helped advance the field of entomology during the late 19th and early 20th centuries. His work often focused on the ecological roles of insects and their interactions with other organisms. Butler is best known for his book, "The Book of Butterflies," published in 1898, which provided detailed descriptions and illustrations of numerous butterfly species. His research laid the groundwork for future studies in entomology and inspired many aspiring naturalists and scientists to explore the world of insects.